TWI671228B - Bicycle rim brake - Google Patents

Abstract

A bicycle rim brake is basically provided with a first brake arm and a hydraulic actuating device. The first brake arm includes a first coupling portion, a first actuating portion, and a first mounting portion that are constructed to pivot about a first pivot axis. The first mounting portion is configured to mount a first friction member and extends from the first coupling portion. The hydraulic actuation device is operatively coupled to the first actuation portion of the first brake arm. The hydraulic actuating device includes a cylinder casing defining a hydraulic volume chamber, a first piston movably disposed in the hydraulic volume chamber of the cylinder volume casing, and a cylinder housing disposed at least in the hydraulic volume chamber. A first sealing member that supports the first piston in part.

Description

Bicycle rim brake

The invention relates generally to bicycle rim brakes. More specifically, the present invention relates to a bicycle rim brake including a hydraulic actuation device for applying actuation force to move at least one brake arm to a braking position.

Bicycles are typically provided with at least one braking device for stopping. Currently, there are a wide variety of bicycle brakes available. One common type of bicycle brake is a rim brake. The rim brake is constructed to apply a braking force to a wheel by clamping a rim of a wheel of a bicycle with a pair of brake shoes attached to a pair of brake arms. There are several configurations of rim brakes available. For example, the rim brake includes a side pull type, a center pull type, and a dual-pivot type. An example of a rim brake is disclosed in US Patent No. 7,677,365 assigned to Shimano, Inc .. These rim brakes are operated using Bowden cables. Recently, hydraulically operated rim brakes have been proposed.

In summary, the disclosure here addresses various features of bicycle rim brakes. In one feature, a bicycle rim brake is provided in which a gap between a friction member and a rim can be automatically adjusted.

In view of the state of the known technology and in accordance with the first aspect of the present invention disclosed herein, a bicycle rim brake is provided that basically includes a first brake arm and a hydraulic actuation device. The first brake arm includes a first coupling portion, a first actuating portion, and a first mounting portion that are constructed to pivot about a first pivot axis. The first mounting portion is configured to mount a first friction member and extends from the first coupling portion. The hydraulic actuation device is operatively coupled to the first actuation portion of the first brake arm. The hydraulic actuating device includes a cylinder casing defining a hydraulic volume chamber, a first piston movably disposed in the hydraulic volume chamber of the cylinder volume casing, and a cylinder housing disposed at least in the hydraulic volume chamber. A first sealing member that supports the first piston in part.

According to a second aspect of the present invention, the bicycle rim brake according to the first aspect is constructed so that the cylinder housing has a first annular recessed portion, and the first sealing member is provided in the first annular recessed portion from the first The annular recess protrudes to support the first piston.

According to a third aspect of the present invention, the bicycle rim brake according to the first aspect is constructed such that the first actuating portion and the first mounting portion are disposed on opposite sides of the first coupling portion.

According to a fourth aspect of the present invention, the bicycle rim brake according to the first aspect further includes a second brake arm including a second coupling portion, a first Two actuating portions, and a second mounting portion, the second mounting portion is constructed to mount a second friction member and extend from the second coupling portion.

According to a fifth aspect of the present invention, the bicycle rim brake according to the fourth aspect is constructed such that the first actuating portion and the first mounting portion are disposed on opposite sides of the first coupling portion, and the second The actuating portion and the second mounting portion are disposed on opposite sides of the second coupling portion.

According to a sixth aspect of the present invention, the bicycle rim brake according to the fourth aspect is constructed so that the hydraulic actuating device further includes a second piston movably disposed in a hydraulic pressure chamber of the cylinder casing, and is provided in A second sealing member on the cylinder casing to support the second piston at least partially within the hydraulic pressure chamber.

According to a seventh aspect of the present invention, the bicycle rim brake according to the sixth aspect is constructed so that the cylinder housing has a first annular recessed portion and a second annular recessed portion, and the first sealing member is provided in the first annular recessed portion. The second sealing member is disposed inside the second annular recessed portion and protrudes from the second annular recessed portion to support the second piston.

According to an eighth aspect of the present invention, the bicycle rim brake according to the sixth aspect is constructed such that the first piston is operatively coupled to the first actuation portion of the first brake arm, and the second piston is operatively Ground is coupled to the second actuation portion of the second brake arm.

According to a ninth aspect of the present invention, the bicycle rim brake according to the sixth aspect is constructed such that the first sealing member is an O-ring made of an elastic material, and the second sealing member is an O-shape made of an elastic material ring.

According to a tenth aspect of the present invention, the bicycle rim brake according to the ninth aspect is constructed such that the first seal member has a rectangular cross-sectional profile with a cylindrical inner surface contacting the first piston, and the second seal member has The rectangular cross-sectional profile has a cylindrical inner surface that contacts the second piston.

According to an eleventh aspect of the present invention, the bicycle rim brake according to the sixth aspect is constructed so that the first annular recessed portion has a trapezoidal cross-sectional profile having a first outer surface, wherein the first outer surface follows the first appearance The first actuating portion facing the first brake arm approaches and gradually increases in diameter, and the second annular recess has a trapezoidal cross-sectional profile with a second outer surface, wherein the second outer surface moves toward the first The second actuation part of the two brake arms approaches and the diameter gradually increases.

According to a twelfth aspect of the present invention, the bicycle rim brake according to the fourth aspect further includes a support member that is coupled to the first and second coupling portions and holds the first and second pivot axes. Separated from each other by a prescribed distance.

According to a thirteenth aspect of the present invention, the bicycle rim brake according to the fourth aspect is constructed so that the first coupling portion includes a first mounting fastener constructed to be mounted on the bicycle, and the second coupling portion Contains a second mounting fastener constructed to be mounted on a bicycle.

According to a fourteenth aspect of the present invention, the bicycle rim brake according to the thirteenth aspect further includes a first return spring biasing the first brake arm toward the first piston about the first pivot axis, and the second brake A second return spring biased by the arm toward the second piston about the second pivot axis.

According to a fifteenth aspect of the present invention, the bicycle rim brake according to the fourth aspect further includes a first adjustment member configured to adjust a biasing force of the first return spring, and a first adjustment member configured to be independent of the first adjustment member. A second adjustment member that adjusts a biasing force of the second return spring.

According to a sixteenth aspect of the present invention, the bicycle rim brake according to the first aspect further includes a first return spring biasing the first brake arm about the first pivot axis toward the first piston.

According to a seventeenth aspect of the present invention, the bicycle rim brake according to the sixteenth aspect further includes a first adjustment member configured to adjust a biasing force of the first return spring.

According to an eighteenth aspect of the present invention, the bicycle rim brake according to the second aspect is constructed such that the first sealing member is an O-ring made of an elastic material.

According to a nineteenth aspect of the present invention, the bicycle rim brake according to the eighteenth aspect is constructed such that the first sealing member has a rectangular cross-sectional profile and has a cylindrical inner surface that contacts the first piston.

According to a twentieth aspect of the present invention, the bicycle rim brake according to the second aspect is constructed such that the first annular recess has a trapezoidal cross-sectional profile having a first outer surface, wherein the first outer surface follows the first appearance The first actuating part facing the first brake arm approaches and gradually increases in diameter Big.

And, for those skilled in the art, other objects, features, aspects, and advantages of the disclosed bicycle rim brake will be apparent from the following detailed description of the embodiment of the bicycle rim brake disclosed with the accompanying drawings. .

Reference is made below to the accompanying drawings which form a part of this original disclosure.

1‧‧‧ bicycle

2‧‧‧ front fork

12‧‧‧ Bicycle rim brake

14‧‧‧first brake arm

14a‧‧‧First coupling part

14b‧‧‧First actuation part

14b1‧‧‧First seat

14c‧‧‧First installation part

16‧‧‧Second brake arm

16a‧‧‧Second coupling part

16b‧‧‧Second actuation part

16b1‧‧‧Second seat

16c‧‧‧Second installation part

18‧‧‧hydraulic actuator

20‧‧‧ support member

22‧‧‧First mounting fastener

24‧‧‧Second mounting fastener

26‧‧‧The first friction member

26a‧‧‧brake pad holder

26b‧‧‧brake pads or brake pads

26c‧‧‧Mounting bolt

28‧‧‧Second friction member

28a‧‧‧brake pad holder

28b‧‧‧brake pad or brake pad

28c‧‧‧Mounting bolt

30‧‧‧First brake arm support unit

32‧‧‧Second brake arm support unit

34‧‧‧ the first return spring

34a‧‧‧First end part

34b‧‧‧Second end part

36‧‧‧Second return spring

36a‧‧‧First end part

36b‧‧‧Second end part

40‧‧‧Crossing component

40a‧‧‧First opening

40b‧‧‧Second opening

42‧‧‧ holding parts

42a‧‧‧Mounting opening

42b‧‧‧Anti-rotation opening

42c‧‧‧Concave

44‧‧‧ Screw

46‧‧‧Mounting sleeve

46a‧‧‧Threaded hole

48‧‧‧ Anti-rotation protrusion

50‧‧‧ first spring attachment protrusion

50a‧‧‧Threaded hole

52‧‧‧ second spring attachment protrusion

52a‧‧‧Threaded hole

54‧‧‧The first adjustment member

56‧‧‧Second adjustment member

60‧‧‧ cylinder housing

60a‧‧‧First annular recess

60a1‧‧‧first outer surface

60a2‧‧‧first axial end wall

60a3‧‧‧Second axial end wall

60b‧‧‧Second annular recess

60b1‧‧‧ second outer surface

61‧‧‧First Piston

61a‧‧‧Concave or socket

62‧‧‧Second Piston

62a‧‧‧Concave or socket

64‧‧‧hydraulic container

64a‧‧‧First room

64b‧‧‧Second Room

64c‧‧‧Third Room

66‧‧‧First connecting rod

66a‧‧‧First end part

66b‧‧‧Second end part

68‧‧‧Second connecting rod

68a‧‧‧First end part

68b‧‧‧Second end part

70‧‧‧first pivot pin

70a‧‧‧Threaded hole

72‧‧‧ second pivot pin

72a‧‧‧Threaded hole

74‧‧‧ entrance hole

76‧‧‧ Drain hole

78‧‧‧Relief Threaded Takeover

81‧‧‧first seal member

81a‧‧‧ cylindrical inner surface

82‧‧‧Second sealing member

82a‧‧‧ cylindrical inner surface

101‧‧‧ Bicycle

102‧‧‧ Front fork

112‧‧‧Bicycle rim brakes

114‧‧‧first brake arm

114a‧‧‧First coupling part

114b‧‧‧First installation part

114c‧‧‧ Highlight

116‧‧‧Second brake arm

116a‧‧‧Second coupling part

116b‧‧‧Second installation part

116c‧‧‧Second actuation part

118‧‧‧hydraulic actuator

120‧‧‧Mounting fasteners

122‧‧‧Actuation link

122a‧‧‧ Attachment structure

122b‧‧‧Coupling Structure

122c‧‧‧Contact

124‧‧‧ pivot pin

126‧‧‧The first friction member

128‧‧‧Second friction member

130‧‧‧ biasing member

132‧‧‧ support member

140‧‧‧ cylinder housing

140a‧‧‧ annular recess

142‧‧‧hydraulic container

144‧‧‧Piston

146‧‧‧Connecting rod

146a‧‧‧First end part

146b‧‧‧Second end part

148‧‧‧ pivot pin

150‧‧‧first sealing member

152‧‧‧Entrance hole

A1‧‧‧ actuation axis

A2‧‧‧Center longitudinal axis

C1‧‧‧ the first pivot axis

C2‧‧‧Second pivot axis

D‧‧‧ prescribed distance

H‧‧‧Hydraulic hose

P1‧‧‧first pivot axis

P2‧‧‧second pivot axis

R‧‧‧ bicycle rim

W‧‧‧ front wheels

FIG. 1 is a front view of a portion of a bicycle equipped with a bicycle rim brake according to a first embodiment, with the bicycle rim brake in a non-braking position or a resting position.

FIG. 2 is a front perspective view of the bicycle rim brake shown in FIG. 1, with the bicycle rim brake in a non-braking position.

3 is a rear perspective view of the bicycle rim brake shown in FIGS. 1 and 2, wherein the bicycle rim brake is in a non-braking position.

Fig. 4 is a rear view of the bicycle rim brake shown in Figs. 1 to 3, with the bicycle rim brake in a non-braking position.

Fig. 5 is a side view of the bicycle rim brake shown in Figs. 1 to 4, with the bicycle rim brake in a non-braking position.

Fig. 6 is a front view of the bicycle rim brake shown in Figs. 1 to 5, in which a part of the support member of the bicycle rim brake is cut away to expose the spring configuration.

Fig. 7 is a view of the bicycle rim brake shown in Figs. Partially exploded perspective view.

FIG. 8 is an exploded perspective view of another portion of selected components of the bicycle rim brake shown in FIGS. 1 to 6.

9 is an exploded perspective view of another selected part of the bicycle rim brake shown in FIGS. 1 to 6 when viewed from the rear side of the bicycle rim brake.

10 is an exploded perspective view of another part of the bicycle rim brake shown in FIGS. 1 to 6 when selected components are viewed from the front side of the bicycle rim brake.

Fig. 11 is a front view of the bicycle rim brake shown in Figs. 1 to 6, in which several parts of the hydraulic actuator are shown in a longitudinal section.

FIG. 12 is a cross-sectional view of a portion of the hydraulic actuation device of the bicycle rim brake shown in FIGS. 1 to 6, showing one of the sealing members in a non-actuated position.

FIG. 13 is a cross-sectional view of a portion of the hydraulic actuation device shown in FIG. 12, but with the piston and the sealing member in an actuated position.

14 is an enlarged cross-sectional profile of a part of one of the sealing members of the hydraulic actuator of the bicycle rim brake shown in FIGS. 1 to 6.

Fig. 15 is a rear view of the bicycle rim brake shown in Figs. 1 to 6, in which the first and second brake arms are held in a position for removing the hydraulic actuator.

Fig. 16 is a view of the bicycle rim brake shown in Figs. A side view of the support member and the holder, in which the cylinder housing of the hydraulic actuator is shown in cross section, and the cylinder housing of the hydraulic actuator is partially removed from the holder of the bicycle rim brake.

Fig. 17 is a rear view of the bicycle rim brake shown in Figs. 1 to 6, in which the first and second brake arms are held at positions for removing the hydraulic actuation device, and the hydraulic actuation device is removed from the bicycle rim brake The holder was removed.

18 is a front view of a portion of a bicycle equipped with a bicycle rim brake according to a second embodiment, with the bicycle rim brake in a non-braking position or a resting position.

FIG. 19 is a side view of the bicycle portion and the bicycle rim brake shown in FIG. 18.

FIG. 20 is a front view similar to FIG. 18 of the bicycle portion and the bicycle rim brake shown in FIG. 18 and FIG. Display to show selected components of the hydraulic actuator.

Selected embodiments are described below with reference to the drawings. It will be apparent to those skilled in the art of bicycles from this disclosure that the description of the following embodiments is provided for illustration only, and is not intended to limit the invention as defined by the accompanying claims and their equivalents.

Reference is first made to FIG. 1, which shows a bicycle 1 with a front fork 2 equipped with a bicycle rim brake 12 according to a first embodiment. a part. The bicycle rim brake 12 is mounted on the front fork 2 such that the bicycle rim brake 12 straddles the bicycle rim R of the front wheel W. Of course, it will be apparent to those skilled in the art of bicycles from this disclosure that the bicycle rim brake 12 can be used with the rear wheels of a bicycle.

The bicycle rim brake 12 basically includes a first brake arm 14, a second brake arm 16, and a hydraulic actuator 18. Although the first embodiment uses two brake arms, the bicycle rim brake 12 may be constructed to have a single brake arm if needed and / or desired. In the first embodiment, the bicycle rim brake 12 is hydraulically actuated by a conventional hydraulic actuating member (for example, a brake lever) not shown. The bicycle rim brake 12 further includes a support member 20. The first and second brake arms 14 and 16 are pivotally supported on the support member 20. In particular, the first brake arm 14 is pivotally supported on the support member 20 by a first mounting fastener 22 constructed to be mounted on the front fork 2 of the bicycle 1. The first mounting fastener 22 defines a first pivot axis P1 of the first brake arm 14. Similarly, the second brake arm 16 is pivotably supported on the support member 20 by a second mounting fastener 24 constructed to be mounted on the front fork 2 of the bicycle 1. The second mounting fastener 24 defines a second pivot axis P2 of the second brake arm 16.

As seen from FIGS. 2, 3, and 6, the hydraulic actuator 18 is mounted on the support member 20. The hydraulic actuator 18 is fluidly connected to the first end of the hydraulic hose H. The hydraulic hose H also has a second end (not shown) connected to a conventional hydraulic actuation member (not shown). In control During the dynamic operation, the hydraulic fluid is forced into the hydraulic actuator 18 to cause the hydraulic actuator 18 to push the first and second brake arms 14 and 16 to apply a braking force to the bicycle rim R.

The hydraulic actuator 18 is operatively coupled between the first brake arm 14 and the second brake arm 16 and is configured to place the first and second brake arms 14 and 16 about the first and second pivot axes, respectively. The lines P1 and P2 pivot. Therefore, the actuation of the hydraulic actuating device 18 causes the first and second brake arms 14 and 16 to pivot as the first and second brake arms 14 and 16 pivot about the first and second pivot axes P1 and P2, respectively. The non-braking position or rest position is moved to the braking position or the actuating position. The pivotal movement of the first and second brake arms 14 and 16 about the first and second pivot axes P1 and P2 respectively applies a braking force to the front wheel W by clamping the bicycle rim R of the front wheel W.

The first and second brake arms 14 and 16 are now discussed in more detail below. Each of the first and second brake arms 14 and 16 is a rigid member made of a suitable rigid material typically used for bicycle brake arms. For example, the first and second brake arms 14 and 16 may be cold-forged aluminum arms or carbon fiber reinforced arms. As can be seen from the view in FIG. 1, the first brake arm 14 is pivoted counterclockwise about the first pivot axis P1 to contact the bicycle rim R, and the second brake arm 16 is pivoted about the second pivot axis P2 Pivot clockwise to contact the bicycle rim R. Therefore, the first brake arm 14 pivots clockwise about the first pivot axis P1 to move away from the bicycle rim R, and the second brake arm 16 pivots counterclockwise about the second pivot axis P2 to move away Bicycle rim R.

As seen in FIGS. 3 and 4, the first brake arm 14 is basically There is a first coupling portion 14a, a first actuation portion 14b, and a first mounting portion 14c. The first moving portion 14b and the first mounting portion 14c are disposed on opposite sides of the first coupling portion 14a. The first coupling portion 14 a includes a first mounting fastener 22 constructed to be mounted on the bicycle 1. Therefore, the first coupling portion 14a is constructed to pivot about the first pivot axis P1. The first actuating portion 14 b extends from the first coupling portion 14 a and is operatively coupled to the hydraulic actuating device 18. The first mounting portion 14 c extends from the first coupling portion 14 a and is constructed to mount the first friction member 26. In the first embodiment, as seen in FIG. 3, the first mounting portion 14 c includes a groove (an elongated opening) for adjustably attaching the first friction member 26. In the first embodiment, the first friction member 26 is a conventional brake pad that is detachably attached to the first mounting portion 14b in a conventional manner. Basically, the first friction member 26 includes a brake pad holder 26a, and a brake pad or a brake pad 26b. The brake pad holder 26a supports the brake pad 26b and is attached to a groove formed in the first mounting portion 14c by a mounting bolt 26c. The brake pad 26b of the first friction member 26 contacts one side of the bicycle rim R during a braking operation.

Similarly, the second brake arm 16 basically has a second coupling portion 16a, a second actuation portion 16b, and a second mounting portion 16c. The second actuating portion 16b and the second mounting portion 16c are disposed on opposite sides of the second coupling portion 16a. The second coupling portion 16 a includes a second mounting fastener 24 constructed to be mounted on the bicycle 1. Therefore, the second coupling portion 16a is constructed to pivot about the second pivot axis P2. Second actuation part 16b Extending from the second coupling portion 16 a and operatively coupled to the hydraulic actuator 18. The second mounting portion 16 c extends from the second coupling portion 16 a and is constructed to mount the second friction member 28. In the first embodiment, as seen in FIG. 2, the second mounting portion 16 c includes a groove (an elongated opening) for adjustably attaching the second friction member 28. In the first embodiment, the second friction member 28 is a conventional brake pad that is detachably attached to the second mounting portion 16b in a conventional manner. Basically, the second friction member 28 includes a brake pad holder 28a, and a brake pad or a brake pad 28b. The brake pad holder 28a supports the brake pad 28b and is attached to a groove formed in the second mounting portion 16c by a mounting bolt 28c. The brake pad 28 b of the second friction member 28 contacts the other side of the bicycle rim R during a braking operation.

In the first embodiment, each of the first coupling portion 14a and the second coupling portion 16a is preferably provided to pivotably support the first and second brake arms 14 and 16 to the first Bushing and / or bearing structures on the second mounting fasteners 22 and 24. Here, the first coupling portion 14 a further includes a first brake arm support unit 30 for rotatably supporting the first brake arm 14 on the first mounting fastener 22. Similarly, the second coupling portion 16 a further includes a second brake arm support unit 32 for rotatably supporting the second brake arm 16 on the second mounting fastener 24. In the first embodiment, each of the first and second brake arm support units 30 and 32 is constructed as disclosed in US Patent Application Publication No. 2013/0341129 assigned to Shimano, Inc.

5, 6, and 8, the first and second brake arms 14 and Each of 16 is biased to its respective non-braking position, and these non-braking positions constitute the rest positions of the first and second brake arms 14 and 16. More specifically, the bicycle rim brake 12 includes a first return spring 34 and a second return spring 36. The first return spring 34 biases the first brake arm 14 about the first pivot axis P1 toward the non-braking position. The second return spring 36 biases the second brake arm 16 about the second pivot axis P2 toward the non-braking position. The first return spring 34 has a first end portion 34a and a second end portion 34b. A first end portion 34 a of the first return spring 34 is attached to an opening formed in the first brake arm 14, and a second end portion 34 b is hooked on the support member 20. Similarly, the second return spring 36 has a first end portion 36a and a second end portion 36b. The first end portion 36 a of the second return spring 36 is attached to an opening formed in the second brake arm 16, and the second end portion 36 b is hooked on the support member 20.

Still referring to FIGS. 5, 6, and 8, the support member 20 includes a cross member 40. The traverse member 40 of the support member 20 is coupled to the first and second coupling portions 14a and 16a, and the first and second pivot axes P1 and P2 are kept apart from each other as seen in FIG. 6 Distance D. The cross member 40 has a first opening 40 a for receiving the first mounting fastener 22 and a second opening 40 b for receiving the second mounting fastener 24.

The support member 20 further includes a holder 42. The holder 42 is supported on the rear side of the traverse member 40. Here, a screw 44 is provided to attach the holder 42 to the traverse member 40. Each of the cross member 40 and the holder 42 is rigid made of a suitable rigid material such as aluminum or carbon fiber member. In the first embodiment, the traverse member 40 and the holder 42 are separate members. However, the traverse member 40 and the holder 42 may be formed as a single-piece member composed of a single individual material.

As will be explained below, the holder 42 is constructed to support the hydraulic actuation device 18 on the first and second brake arms 14 and 16 via the cross member 40 with a toolless connection, so that the hydraulic actuation is performed The device 18 can be removed from the holder 42 and reinstalled on the holder 42. In this manner, the hydraulic actuator 18 can be removed from the holder 42 and then reinstalled without removing the first and second brake arms 14 and 16 from the front fork 2.

As seen in FIGS. 6 and 8, the mounting sleeve 46 extends from the rear side of the cross member 40 into the mounting opening 42 a of the holder 42. The mounting sleeve 46 has a screw hole 46a. The screw 44 is screwed into the threaded hole 46 a to attach the holder 42 to the cross member 40. And, the anti-rotation protrusion 48 extends from the rear side of the traverse member 40 and engages the anti-rotation opening 42 b of the holder 42. The holder 42 includes a recess 42 c that receives the hydraulic actuator 18. As will be explained below, the hydraulic actuator 18 can be snap-fitted into and withdrawn from the recess 42c to align the hydraulic actuator 18 with respect to the first and second brake arms 14 and 16 installation and removal.

As seen in FIGS. 6 and 8, the rear side of the traverse member 40 has a first spring attachment protrusion 50 and a second spring attachment protrusion 52. The first spring attachment protrusion 50 is a headed pin for attaching the second end portion 34 b of the first return spring 34. In the first embodiment In this case, the biasing force of the first and second return springs 34 and 36 can be adjusted. Specifically, the first spring attachment protrusion 50 is provided with a screw hole 50a. The screw hole 50 a receives a first adjustment member 54 configured to adjust a biasing force of the first return spring 34 with a screw. The second spring attachment protrusion 52 is a headed pin for attaching the second end portion 36 b of the second return spring 36. The second spring attachment protrusion 52 is provided with a screw hole 52a. The screw hole 52 a receives a second adjustment member 56 configured to adjust the biasing force of the second return spring 36 independently of the first adjustment member 54 with a thread. In the first embodiment, the first and second adjustment members 54 and 56 are set screws. By screwing in and out the first and second adjustment members 54 and 56 independently of each other, the user can adjust the biasing forces of the first and second return springs 34 and 36 independently of each other. However, the first and second adjustment members 54 and 56 may have other configurations, such as cams, which may be rotated independently of each other on the first and second spring attachment protrusions 50 and 52 to change the first And the positions of the first and second end portions 34b and 36b of the second return springs 34 and 36.

The hydraulic actuator 18 will now be described in more detail below. Basically, the hydraulic actuation device 18 is supported on the support member 20 and is operatively coupled to the first and second actuation portions 14b and 16b of the first and second brake arms 14 and 16. The hydraulic hose H is connected between a conventional hydraulic actuating member (for example, a brake lever) and a hydraulic actuating device 18 (not shown). The hydraulic hose H supplies hydraulic fluid to the hydraulic actuation device 18 in response to the operation of a conventional hydraulic actuation member (for example, a brake lever).

As seen in FIG. 11, the hydraulic actuation device 18 includes The cylinder housing 60, the first piston 61, and the second piston 62. The cylinder housing 60 defines a hydraulic reservoir 64. The first piston 61 is movably disposed in the hydraulic pressure chamber 64. The hydraulic pressure storage chamber 64 includes a first storage chamber 64a, a second storage chamber 64b, and a third storage chamber 64c. A first piston 61 is provided inside the first accommodating chamber 64a. A second piston 62 is provided inside the second accommodating chamber 64b. The third storage chamber 64c is disposed between the first storage chamber 64a and the second storage chamber 64b. The third receiving chamber 64c has a smaller diameter than the first and second receiving chambers 64a and 64b. In this configuration, the hydraulic hose H supplies hydraulic fluid to the third chamber 64c to simultaneously actuate the first and second pistons 61 and 62.

The outer dimensions of the cylinder case 60 are such that the cylinder case 60 can be snapped into and pulled out from the recessed portion 42 c of the holder 42. In this way, the hydraulic actuator 18 can be removed and reinstalled relative to the first and second brake arms 14 and 16 without using tools. In particular, the holder 42 is constructed to have elasticity such that the cylinder housing 60 is snapped into the recess 42 c of the holder 42. In other words, the outside of the cylinder housing 60 is sized to be slightly larger than the opening of the recessed portion 42 c of the holder 42. As a result, when the cylinder housing 60 of the hydraulic actuator 18 is pushed into or pulled out from the concave portion 42 c of the holder 42, the holder 42 is elastically deformed. In this manner, the recessed portion 42 c of the holder 42 receives the cylinder housing 60 of the hydraulic actuator 18 so that the cylinder housing 60 is retained within the recess 42 c of the holder 42.

The first piston 61 is movably disposed in the hydraulic pressure chamber 64. The first piston 61 is operatively coupled to the first actuating portion 14 b of the first brake arm 14. In particular, the hydraulic actuator 18 includes a The first actuating portion 14 b of the boom 14 is connected to the first connecting rod 66 of the first piston 61. Therefore, the first actuating portion 14 b of the first brake arm 14 is operatively coupled to the first piston 61 via the first connecting rod 66. The second piston 62 is movably disposed in the hydraulic pressure chamber 64. The second piston 62 is operatively coupled to the second actuating portion 16 b of the second brake arm 16. In particular, the hydraulic actuation device 18 includes a second connecting rod 68 that connects the second actuation portion 16 b of the second brake arm 16 to the second piston 62. Therefore, the second actuating portion 16 b of the second brake arm 16 is operatively coupled to the second piston 62 via the second connecting rod 68.

As described above, the first return spring 34 biases the first brake arm 14 toward the first piston 61 about the first pivot axis P1. Therefore, the first connecting rod 66 exerts a thrust force on the first piston 61 as a result of the biasing force of the first return spring 34 acting on the first brake arm 14. As also described above, the second return spring 36 biases the second brake arm 16 toward the second piston 62 about the second pivot axis P2. Therefore, the second connecting rod 68 exerts a thrust force on the second piston 62 as a result of the biasing force of the second return spring 36 acting on the second brake arm 16.

As seen in FIGS. 9 to 11, the first connecting rod 66 has a first end portion 66 a connected to the first piston 61 and a second end portion connected to the first actuation portion 14 b. 66b. The first end portion 66 a of the first connecting rod 66 is constructed to be pivotably and detachably coupled to the first piston 61. In the first embodiment, the first end portion 66 a of the first connecting rod 66 includes a part of a spherical member or a sphere that is received in the recess or the seat 61 a of the first piston 61. The first connecting rod 66 is pivotably Connected to the first brake arm 14. The first connecting rod 66 includes a first pivot pin 70 disposed in the first socket 14b1 of the first actuating portion 14b of the first brake arm 14. The first connecting rod 66 is adjustably connected to the first brake arm 14. In the first embodiment, the second end portion 66b of the first connecting rod 66 has a thread. The second end portion 66 b is screwed into the threaded hole 70 a of the first pivot pin 70 to adjustably couple the first connecting rod 66 to the first brake arm 14. The end of the second end portion 66b has a tool receiving recess for rotating the first connecting rod 66 to adjust the rest position of the first brake arm 14. In this way, the first connecting rod 66 is constructed to remain attached to the first brake arm 14 in a state where the hydraulic actuator 18 is removed.

As seen in FIGS. 9 to 11, the second connecting rod 68 has a first end portion 68 a connected to the second piston 62 and a second end portion connected to the second actuation portion 16 b. 68b. The second connecting rod 68 is pivotably connected to the second brake arm 16. The first end portion 68 a of the second connecting rod 68 is constructed to be pivotably and detachably coupled to the second piston 62. In the first embodiment, the first end portion 68 a of the second connecting rod 68 includes a part of a spherical member or a sphere that is received in the recess or the seat 62 a of the second piston 62. The second connecting rod 68 includes a second pivot pin 72 disposed in the second socket 16 b 1 of the second actuating portion 16 b of the second brake arm 16. The second connecting rod 68 is adjustably connected to the second brake arm 16. In the first embodiment, the second end portion 68b of the second connecting rod 68 has a thread. The second end portion 68 b is screwed into the threaded hole 72 a of the second pivot pin 72 to adjustably couple the second connecting rod 68 to the second brake arm 16. Tool receiving recess at the end of the second end portion 68b Part for rotating the second connecting rod 68 to adjust the rest position of the second brake arm 16. In this manner, the second connecting rod 68 is constructed to remain attached to the second brake arm 16 in a state where the hydraulic actuator 18 is removed.

As seen in FIGS. 11 and 16, the cylinder housing 60 includes an inlet hole 74 in fluid communication with the hydraulic pressure chamber 64 at a position between the first piston 61 and the second piston 62. In particular, the inlet hole 74 is in fluid communication with the third storage chamber 64c of the hydraulic storage chamber 64 to supply hydraulic fluid to the third storage chamber 64c, and is used to move within the first and second storage chambers 64a and 64b of the hydraulic storage chamber 64. The first and second pistons 61 and 62. The first and second pistons 61 and 62 are movable along the actuation axis A1 of the hydraulic chamber 64. The inlet hole 74 has a central longitudinal axis A2 that is vertically arranged with respect to the actuation axis A1 of the hydraulic pressure chamber 64. The cylinder housing 60 further includes a bleeding bore 76, and a bleeding nipple 78 is screwed into the bleeding bore 76.

As seen in FIGS. 11 to 14, the hydraulic actuating device 18 includes a first sealing member 81 that is provided on the cylinder housing 60 to be at least partially supported in the hydraulic tank 64. First piston 61. As seen in FIG. 11, the hydraulic actuation device 18 includes a second sealing member 82 that is disposed on the cylinder housing 60 to at least partially support the second in the hydraulic pressure chamber 64. Piston 62. The first and second sealing members 81 and 82 are the same as each other in the first embodiment. The cylinder housing 60 includes a first annular recessed portion 60a and a second annular recessed portion 60b. The first sealing member 81 is provided in the first annular recessed portion 60 a and protrudes from the first annular recessed portion 60 a to support the first piston 61. The second sealing member 82 is provided in the second annular recessed portion 60 b and protrudes from the second annular recessed portion 60 b to support the second piston 62. The first and second annular recesses 60a and 60b are opposed to each other. The same except that the two are mirror images of each other in the first embodiment. The first and second annular recesses 60a and 60b are provided with sufficient axial dimensions so that the first and second sealing members 81 and 82 can contact the cylinder housing during the movement of the first and second pistons 61 and 62. Before 60, it was deflected in the axial direction along the actuation axis A1. The first annular recess 60 a has a trapezoidal cross-sectional profile having a first outer surface 60 a 1, wherein the first outer surface 60 a 1 approaches the first actuating portion 14 b of the first brake arm 14 with the first outer surface 60 a 1. The diameter gradually increases. The first annular recess 60a further includes a first axial end wall 60a2 and a second axial end wall 60a3, and the first outer surface 60a1 connects the first axial end wall 60a2 and the second axial end wall 60a3. The second axial end wall 60a3 is arranged closer to the first brake arm 14 than the first axial end wall 60a2. The second annular recessed portion 60 b has a trapezoidal cross-sectional profile having a second outer surface 60 b 1, wherein the second outer surface 60 b 1 approaches the second actuating portion 16 b of the second brake arm 16 with the second outer surface 60 b 1. The diameter gradually increases. Therefore, the first and second outer surfaces 60a1 and 60b1 are inclined with respect to the actuation axis A1 so that the outer diameters of the first and second annular recesses 60a and 60b become larger as the first and second annular recesses 60a and 60b become larger. The distance away from the central longitudinal axis A2 of the entrance hole 74 becomes larger. The phrase "trapezoidal cross-section profile" used in relation to the first and second annular recesses 60a and 60b here means that the overall shape of each recess is a trapezoid having two parallel sides and two non-parallel sides, Each corner may be rounded and / or truncated, and one or more of the sides may be non-planar.

The first sealing member 81 is made of a flexible, resilient, or elastic material suitable for hydraulic applications, such as a rubber material. The second sealing member 82 is made of the same flexible, resilient, or elastic material as the first sealing member 81 to make. The first and second sealing members 81 and 82 create a seal between the cylinder housing 60 and the first and second pistons 61 and 62 to prevent hydraulic fluid from leaking to the hydraulic pressure through the first and second pistons 61 and 62. The exterior of the accommodation chamber 64. The first sealing member 81 is an O-ring having a rectangular cross-sectional profile, and has a cylindrical inner surface 81 a contacting the first piston 61. The second sealing member 82 is an O-ring having a rectangular cross-sectional profile, and has a cylindrical inner surface 82 a that contacts the second piston 62. The phrase “cross-sectional profile” used herein in relation to the first and second sealing members 81 and 82 refers only to a cross-section of a section of the sealing member as shown in the sections of FIGS. 12 to 14. The phrase “cross-sectional profile” used herein in relation to the first and second sealing members 81 and 82 does not refer to the transverse section of the entire sealing member. The phrase “rectangular shape” used here with respect to the first and second sealing members 81 and 82 refers to an overall shape of a rectangle having four planar side surfaces and two opposite side surfaces parallel to each other, wherein each corner may be a circle Angular and / or truncated.

12 to 14, the first and second sealing members 81 and 82 are constructed to automatically provide a brake pad gap between the bicycle rim R and the brake pads 26 b and 28 b after the actuation of the bicycle rim brake 12. Adjustment. In particular, when the brake lever is returned to the rest position after actuation, the first and second sealing members 81 and 82 return the first and second pistons 61 and 62 to the first and second pistons 61 and 62. The respective initial positions thus provide a running clearance between the bicycle rim R and the brake pads 26b and 28b. More specifically, when the first piston 61 is axially moved from the rest position (FIG. 12) along the actuation axis A1 in the hydraulic pressure chamber 64 to the actuation position (FIG. 13), the first seal member 81 is as The skew in the axial direction is seen in FIG. 13. Actuation in Figure 13 Position, the first sealing member 81 is temporarily deformed. The deformation caused by the first sealing member 81 causes the first sealing member 81 to exert a piston restoring force on the first piston 61. Therefore, once the hydraulic pressure in the hydraulic pressure chamber 64 is reduced, the first sealing member 81 acts on the first piston 61 to return the first piston 61 to the rest position as seen in FIG. 12. The first sealing member 81 is separated from the first axial end wall 60a2 and the second axial end wall 60a3 by a predetermined distance, so that the first sealing member 81 is in the operation period of the first piston 61 between the rest position and the braking position. Spaced from the second axial end wall 60a3.

Before any wear of the brake pads 26 b and 28 b occurs, the movement of the first piston 61 causes the first sealing member 81 to deflect, but the first piston 61 does not slide on the first sealing member 81. When the brake pads 26b and 28b are worn, the actuation of the first piston 61 will cause the first sealing member 81 to deflect first, and then the first piston 61 will slide on the first sealing member 81 to offset the brake pads 26b and 28b. Wear of 28b. Therefore, a new rest position is established when the first sealing member 81 acts on the first piston 61 to return the first piston 61 to the rest position. The second sealing member 82 operates in the same manner as the first sealing member 81.

Referring now to FIGS. 18 to 20, a portion of a bicycle 101 with a front fork 102 equipped with a bicycle rim brake 112 according to a second embodiment is shown. Here, the bicycle rim brake 112 basically includes a first brake arm 114, a second brake arm 116, and a hydraulic actuator 118. The bicycle rim brake 112 also includes a single mounting fastener 120 that pivotally connects the first and second brake arms 114 and 116 about a first pivot axis C1. Second embodiment and The first embodiment is different in that both the first and second brake arms 114 and 116 pivot about the first pivot axis C1. The bicycle rim brake 112 also includes an actuation link 122 that is pivotably mounted on the second brake arm 116 by a pivot pin 124 about a second pivot axis C2, wherein the second pivot shaft The line C2 deviates from the first pivot axis C1. The bicycle rim brake 112 further includes a first friction member 126 attached to the first brake arm 114 and a second friction member 128 attached to the second brake arm 116.

As seen in FIG. 19, preferably, the bicycle rim brake 112 also includes a biasing member 130. In this embodiment, the biasing member 130 is a torsion spring. The biasing member 130 has a spiral portion provided around the mounting fastener 120 and a pair of free end portions that engage the first and second brake arms 114 and 116, respectively. The first and second brake arms 114 and 116 are biased to a non-braking position or a rest position (FIG. 18). Therefore, the brake pads of the first and second friction members 126 and 128 are held in the pre-loaded open state by the biasing member 130.

In this embodiment, the hydraulic actuator 118 is mounted to the second brake arm 116 via the support member 132. The support member 132 is the same as the holder 42 of the first embodiment, except that the support member 132 is directly mounted to the second brake arm 116 by a fastener (not shown). In other words, the support member 132 is the same as the holder 42 except that the mounting opening 42a and the anti-rotation opening 42b are located so that the mounting opening of the support member 132 is aligned with the screw hole of the second brake arm 116 and the The anti-rotation opening directly engages the anti-rotation protrusion of the second brake arm 116. Therefore, as in the first embodiment, the hydraulic actuator 118 can be snapped The support member 132 and the support member 132 are pulled out to mount and dismount the hydraulic actuator 118 with respect to the first and second brake arms 114 and 116.

The hydraulic actuation device 118 is now described in more detail below. Basically, the hydraulic actuator 118 is supported on a support member 132 and is operatively coupled to the first and second brake arms 114 and 116 via an actuation link 122. The hydraulic actuation device 118 includes a cylinder housing 140, a piston 144, and a connecting rod 146 that define a hydraulic chamber 142. The piston 144 and the connecting rod 146 are the same as the first piston 61 and the first connecting rod 66. Accordingly, the connecting rod 146 has a first end portion 146 a that is engaged with the piston 144 and a second end portion 146 b that is adjustably engaged with a pivot pin 148 rotatably mounted on the actuation link 122.

The hydraulic actuator 118 further includes a first sealing member 150 that is disposed on the cylinder housing 140 to at least partially support the piston 144 in the hydraulic chamber 142. The first sealing member 150 is the same as the first sealing member 81 of the first embodiment. The first sealing member 150 is provided in the annular recess 140 a of the cylinder case 140. The annular recess 140a and the first sealing member 150 are constructed to provide automatic adjustment of the brake pad gap.

In the second embodiment, the bicycle rim brake 112 is hydraulically actuated by a conventional hydraulic actuating member (for example, a brake lever) not shown. A hydraulic hose H is connected to the inlet hole 152 to supply a hydraulic fluid to the hydraulic pressure chamber 142. Basically, the hydraulic fluid in the hydraulic reservoir 142 is caused by a conventional hydraulically actuated member (e.g., a brake lever). The piston 144 moves inside the hydraulic pressure chamber 142 while being pressurized. This movement of the piston 144 will move the connecting rod 146, which in turn will move the actuation link 122. This movement of the actuation link 122 causes the first and second brake arms 114 and 116 to pivot about the first pivot axis C1 to apply a braking force to the front wheel W by clamping the bicycle rim R of the front wheel W .

The hydraulic actuator 118 is the same as the hydraulic actuator 18 of the first embodiment, except that the cylinder housing 140 has been modified to conform to a single piston configuration and the inlet hole 152 has an elbow shape. In view of the similarity between the hydraulic actuation device 18 and the hydraulic actuation device 118, the hydraulic actuation device 118 will not be discussed and / or shown in detail for the sake of brevity.

The first and second brake arms 114 and 116 are now discussed in more detail below. Each of the first and second brake arms 114 and 116 is a rigid member made of a suitable rigid material typically used for bicycle brake arms. For example, the first and second brake arms 114 and 116 may be cold-forged aluminum arms or carbon fiber reinforced arms. As can be seen from the view in FIG. 18, the first brake arm 114 is pivoted counterclockwise about the first pivot axis C1 to contact the bicycle rim R, and the second brake arm 116 is pivoted about the first pivot axis C1. Pivot clockwise to contact the bicycle rim R. Therefore, the first brake arm 114 is pivoted clockwise about the first pivot axis C1 to move away from the bicycle rim R, and the second brake arm 116 is pivoted counterclockwise about the first pivot axis C1 to move away Bicycle rim R.

Basically, the first brake arm 114 has a first coupling portion 114a, a first mounting portion 114b, and a protruding portion 114c for contacting the actuation link 122. The protruding portion 114c constitutes the first portion of the first brake arm 114. Act in unison. The first coupling portion 114a is constructed to pivot about a first pivot axis C1. The first coupling portion 114 a is pivotably coupled to the mounting fastener 120, and the mounting fastener 120 pivotally mounts the first brake arm 114 relative to the front fork frame 102. The first mounting portion 114b extends from the first coupling portion 114a. The first mounting portion 114b is constructed to mount a first friction member 126 that is the same as the first friction member 26 discussed above. The protruding portion 114c (the first actuation portion) contacts the actuation link 122, so that the thrust of the hydraulic actuation device 118 is transmitted to the first brake arm 114 via the actuation link 122.

Basically, the second brake arm 116 has a second coupling portion 116a, a second mounting portion 116b, and a second actuation portion 116c. The second coupling portion 116a is constructed to pivot about the first pivot axis C1. The second coupling portion 116 a is pivotably coupled to the mounting fastener 120, and the mounting fastener 120 pivotally mounts the second brake arm 116 relative to the front fork frame 102. Therefore, the mounting fastener 120 pivotally connects the first and second coupling portions 114a and 116a together. The second mounting portion 116b extends from the second coupling portion 116a. The second mounting portion 116b is constructed to mount a second friction member 128 that is the same as the second friction member 28 discussed above. The second actuation portion 116c has an opening for mounting the pivot pin 124 so that the thrust of the hydraulic actuation device 118 is transmitted to the second brake arm 116 via the actuation link 122.

The actuation link 122 is now discussed in more detail below. The actuation link 122 is a rigid member made of a suitable rigid material, such as a material for the first and second brake arms 114 and 116. For example, the actuation link 122 may be formed of an aluminum alloy or a carbon fiber reinforced material. The actuation link 122 functions as a connection structure between the first and second brake arms 114 and 116 and the hydraulic actuation device 118. The actuation link 122 has an attachment structure 122a, a coupling structure 122b, and a contact portion 122c.

Here, the attachment structure 122 a has a fork shape (a pair of flanges separated by a gap) straddling the second actuating portion 116 c of the second brake arm 116. Each flange of the attachment structure 122a has a hole that receives a pivot pin 124 that defines a second pivot axis C2. Both ends of the pivot pin 124 are respectively pressed into two holes fitted in the attachment structure 122a. As such, the actuation link 122 is pivotally mounted to the second actuation portion 116c of the second brake arm 116 via the pivot pin 124.

The coupling structure 122 b is constructed to be coupled with the hydraulic actuator 118. Here, the coupling structure 122b has a fork shape (a pair of flanges separated by a gap) straddling the second end portion 146b of the connecting rod 146. Each flange of the coupling structure 122b has a hole that receives the pivot pin 148. The two ends of the pivot pin 148 are free to pivot in the two holes of the coupling structure 122b, respectively. As such, the pivot pin 148 forms a trunnion relative to the actuation link 122. The second end portion 146 b of the connecting rod 146 is screwed into a threaded hole (not shown) of the pivot pin 148 to adjustably couple the connecting rod 146 to the actuating link 122.

In understanding the scope of the present invention, the term "comprising" and its derivatives as used herein mean to clearly define the existence of the described features, elements, components, groups, integers, and / or steps but do not exclude other unmentioned And the existence of features, components, components, groups, integers, and / or steps Open-ended terminology. This also applies to words with similar meanings, such as the terms "including", "having", and their derivatives. Also, the terms "part," "section," "portion," "member," or "element" when used in the singular can have the dual meaning of a single part or a plurality of parts unless stated to the contrary.

The following directional terms used herein are "frame-facing side", "non-frame-facing side", "forward", "backward", "front", "rear", "up", "down", "upper" Below These directions refer to bicycles in the upright riding position and equipped with bicycle rim brakes. Therefore, these directional terms when used to describe bicycle rim brakes should be interpreted relative to a bicycle that is in an upright riding position on a horizontal surface and is equipped with a bicycle rim brake. The terms "left" and "right" are used to indicate the "right" side when referring to the right side when viewed from the rear of the bicycle and the "left" side when referring to the left side when viewed from the rear of the bicycle.

Also, it should be understood that although the terms "first" and "second" may be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, for example, without departing from the teachings of the present invention, the first component discussed above may be referred to as the second component and vice versa. The term "attached" or "attached" as used herein encompasses fixing an element directly to another element by directly attaching the element to another element. A configuration of an element, a configuration of indirectly fixing the element to the other element by attaching the element to one or more intermediate elements and attaching the one or more intermediate elements to the other element, And a configuration in which one element is integrated with another element, that is, one element is substantially a part of another element. This definition also applies to words with similar meanings, such as the terms "joined", "connected", "coupled", "installed", "coupled", "fixed" and their derivatives. Finally, degree terms such as "substantially or substantially", "approximately or approximately", and "approximately or approximately" mean that the terms that they modify have a deviation amount such that the final result does not change significantly.

Although only selected embodiments are selected to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that without departing from the scope of the present invention as defined in the accompanying patent application scope claims, Implement various changes and amendments. For example, unless explicitly stated otherwise, the size, shape, location, or orientation of the various components may be changed as needed and / or desired, as long as these changes do not substantially affect the function that they are intended to achieve. Unless explicitly stated otherwise, components that are shown to be directly connected or contacting each other may have intermediate structures disposed therebetween, as long as these changes do not substantially affect the function that they are intended to achieve. The function of one element may be performed by two elements and vice versa unless explicitly stated otherwise. The structure and functions of one embodiment can be adopted in another embodiment. All advantages need not be present in a particular embodiment at the same time. Each unique feature that is different from the conventional technology, whether alone or in combination with other features, shall also be considered as a further feature of the applicant The separate description of the invention includes the structural and / or functional concepts embodied by such features. Therefore, the above description of the embodiments according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting the present invention as defined by the accompanying claims and their equivalents.

Claims (19)

A bicycle rim brake includes a first brake arm including a first coupling portion, a first actuation portion, and a first mounting portion that are constructed to pivot about a first pivot axis. A mounting portion is constructed to mount a first friction member and extend from the first coupling portion; and a hydraulic actuating device operatively coupled to the first actuation portion of the first brake arm The hydraulic actuating device includes a cylinder casing defining a hydraulic chamber, and the cylinder casing has a first annular recess, the first annular recess includes a first axial end wall, a second axial end wall, And a first outer surface connecting the first axial end wall and the second axial end wall, the first axial end wall and the second axial end wall being opposite walls of the first annular recess, the A first outer surface is located radially outward of the first axial end wall and the second axial end wall, and the second axial end wall is configured closer to the first brake than the first axial end wall. An arm, a first piston movably disposed in the hydraulic volume chamber of the cylinder casing, and an arm disposed on the cylinder casing to adjust the hydraulic pressure A first sealing member that at least partially supports the first piston in the room, the first sealing member being disposed in the first annular recess and between the first axial end wall and the second axial end wall Protruding from the first annular recessed portion to support the first piston in the hydraulic volume, the first sealing member is spaced a predetermined distance from the first axial end wall and the second axial end wall such that the first The sealing member is spaced from the second axial end wall during operation of the first piston between a resting position and a braking position. The bicycle rim brake according to item 1 of the scope of patent application, wherein the first actuating portion and the first mounting portion are disposed on opposite sides of the first coupling portion. The bicycle rim brake according to item 1 of the patent application scope, further comprising: a second brake arm including a second coupling portion and a second actuating portion which are constructed to pivot about a second pivot axis. And a second mounting portion, the second mounting portion is constructed to mount a second friction member and extends from the second coupling portion. The bicycle rim brake according to item 3 of the patent application scope, wherein the first actuating portion and the first mounting portion are disposed on opposite sides of the first coupling portion, and the second actuating portion The moving part and the second mounting part are disposed on opposite sides of the second coupling part. The bicycle rim brake according to item 3 of the patent application scope, wherein the hydraulic actuating device further includes a second piston movably disposed in the hydraulic volume chamber of the cylinder casing, and the cylinder is disposed in the cylinder. A second sealing member on the barrel housing to support the second piston at least partially within the hydraulic volume chamber. The bicycle rim brake according to item 5 of the scope of patent application, wherein the cylinder housing has a second annular recessed portion, and the second sealing member is disposed in the second annular recessed portion from the second annular recessed portion. The recess protrudes to support the second piston. The bicycle rim brake according to item 5 of the patent application scope, wherein the first piston is operatively coupled to the first actuating portion of the first brake arm, and the second piston is operatively The second actuating portion is coupled to the second brake arm. The bicycle rim brake according to item 5 of the application, wherein the first sealing member is an O-ring made of an elastic material, and the second sealing member is an O-ring made of an elastic material. The bicycle rim brake according to item 8 of the scope of patent application, wherein the first seal member has a rectangular cross-sectional profile and has a cylindrical inner surface contacting the first piston, and the second seal member has a rectangular shape The cross-sectional profile has a cylindrical inner surface that contacts the second piston. The bicycle rim brake according to item 5 of the patent application scope, wherein the first annular recessed portion has a trapezoidal cross-sectional profile having a first outer surface, and the first outer surface follows the first outer surface toward the first The first actuating portion of the brake arm approaches and gradually increases in diameter, and the second annular recessed portion has a trapezoidal cross-sectional profile with a second outer surface, and the second outer surface moves toward the The second actuating portion of the second brake arm approaches and gradually increases in diameter. The bicycle rim brake according to item 3 of the patent application scope, further comprising: a supporting member coupled to the first and second coupling portions and maintaining the first and second pivot axes at each other Separate the specified distance. The bicycle rim brake according to item 3 of the scope of patent application, wherein the first coupling portion includes a first mounting fastener that is constructed to be installed on the bicycle, and the second coupling portion includes a construction member that is constructed A second mounting fastener to be mounted on the bicycle. The bicycle rim brake according to item 12 of the patent application scope, further comprising: a first return spring biasing the first brake arm toward the first piston about the first pivot axis; and a second return A spring that biases the second brake arm about the second pivot axis toward the second piston. The bicycle rim brake according to item 13 of the scope of patent application, further comprising: a first adjustment member configured to adjust a biasing force of the first return spring; and a second adjustment member configured to interact with the The first adjustment members adjust the biasing force of the second return spring independently of each other. The bicycle rim brake according to item 1 of the scope of patent application, further comprising: a first return spring biasing the first brake arm toward the first piston about the first pivot axis. The bicycle rim brake according to item 15 of the scope of patent application, further comprising: a first adjustment member configured to adjust a biasing force of the first return spring. The bicycle rim brake according to item 1 of the patent application scope, wherein the first sealing member is an O-ring made of an elastic material. The bicycle rim brake according to claim 17 in which the first seal member has a rectangular cross-sectional profile and has a cylindrical inner surface that contacts the first piston. The bicycle rim brake according to item 1 of the patent application scope, wherein the first annular recessed portion has a trapezoidal cross-sectional profile having a first outer surface, and the first outer surface moves toward the first outer surface with the first outer surface. The first actuation portion of the brake arm approaches and gradually increases in diameter.